A programming convention

Why dthen not introducing a higher order function. After
all, we use a functional language ;0)
> lookupQ(Key, Dict) ->
> case (catch lookup(Key, Dict)) of
> {'EXIT', Why} ->
> {error, Why};
> Other ->
> {ok, Other}
> end.
In the Erlang style:
query(F,Args) ->
case (catch F(Args)) of
{'EXIT',Why}
{error,Why};
Other ->
{ok,Other}
end.
in case of lookupQ(Key,Dict) you write:
query(lookup,[Key,Dict])
This makes is very easy to find the places in you code
where you use this design pattern. The Q as addition is
more add-hoc and not as clear from a program analysis
point of view.
Alternatively, in a more curried style, one could define
several functions and write:
query(lookup)(Key,Dict)
For this one needs about ten functions of the form:
query(F) ->
fun(X1) ->
case (catch F(X1)) of
{'EXIT',Why}
{error,Why};
Other ->
{ok,Other}
end
end.
query(F) ->
fun(X1,X2) ->
case (catch F(X1,X2)) of
{'EXIT',Why}
{error,Why};
Other ->
{ok,Other}
end
end.
etcetera
/Thomas
---
Thomas Arts
Ericsson